Acute phase reactants of mice. I. Isolation of serum amyloid P-component (SAP) and its induction by a monokine.
The acute phase reactant of mice, serum amyloid P-component (SAP), was purified and separated from C-reactive protein (CRP). The purified SAP is composed of identical M, 31 Kd polypeptide subunits, determined by SDS-PAGE. SAP levels increased five-fold by 24 hr after challenge with lipopolysaccharide (LPS) or thioglycollate. This response closely correlated with blood monocytosis and required new macromolecule (protein + RNA) synthesis and secretion by the liver. The induction of the SAP response was adoptively transferred by a serum factor produced in optimal concentrations only 90 min after an inflammatory stimulus, which preceded a detectable increase in SAP. A potent SAP inducer was identified in culture supernatants of LPS-activated macrophages. The rapid induction of SAP synthesis in LPS-unresponsive C3H/HeJ mice was dependent on the amount of lymphocyte-activating factor, LAF(IL 1), present in the macrophage culture supernatants. Partially purified human IL 1 also induced a rapid increase in SAP. Thus the induction of SAP in mice appears to be mediated by a product of macrophages, a cell population that is also expanded as part of the systemic inflammatory response.
D000682:Amyloid / Q000302:isolation & purification*; D000818:Animals; D001665:Binding Sites; D002097:C-Reactive Protein / Q000302:isolation & purification / Q000378:metabolism; D005260:Female; D007249:Inflammation / Q000097:blood; D007375:Interleukin-1; D007700:Kinetics; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008813:Mice, Inbred ICR; D009000:Monocytes; D015846:Monokines; D011506:Proteins / Q000494:pharmacology*; D011817:Rabbits; D000685:Serum Amyloid A Protein / Q000096:biosynthesis / Q000302:isolation & purification* / Q000378:metabolism
D000682:Amyloid; D007375:Interleukin-1; D008070:Lipopolysaccharides; D015846:Monokines; D011506:Proteins; D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein